Wellbores or boreholes may be drilled to, for example, locate and produce hydrocarbons. During a drilling operation, it may be desirable to evaluate and/or measure properties of encountered formations and formation fluids. In some cases, a drillstring is removed and a wireline tool deployed into the borehole to test, evaluate and/or sample the formations and/or formation fluid(s). In other cases, the drillstring may be provided with devices to test and/or sample the surrounding formations and/or formation fluid(s) without having to remove the drillstring from the borehole.
Formation evaluation may involve drawing fluid from the formation into a downhole tool for testing and/or sampling. Various devices, such as probes and/or packers, may be extended from the downhole tool to isolate a region of the wellbore wall, and thereby establish fluid communication with the subterranean formation surrounding the wellbore. Fluid may then be drawn into the downhole tool using the probe and/or packer. Within the downhole tool, the fluid may be directed to one or more fluid analyzers and sensors that may be employed to detect properties of the fluid while the downhole tool is stationary within the wellbore.